1. Field of the Invention
The present invention relates to an X-ray analyzer and a mapping analysis method which are suitable for performing X-ray mapping analysis through, for example, fluorescent X-ray analysis.
2. Description of the Related Art
In fluorescent X-ray analysis, an X-ray emitted from an X-ray source irradiates a sample, and a fluorescent X-ray generated from the sample is detected by an X-ray detector. Then, a signal processing portion counts X-ray signals. From the obtained spectrum, qualitative analysis or quantitative analysis of the sample is performed.
The fluorescent X-ray analysis enables non-destructive and quick analysis, and in recent years, sensitivity of the X-ray analysis has been increased, which enables trace element measurement. Accordingly, the fluorescent X-ray analysis is used as means for detecting a harmful substance contained in a material, a composite electronic component, or the like (see, for example, Japanese Patent Application Laid-open Nos. 2006-119108 and 2007-163183).
In addition, as to X-ray mapping, there is known an X-ray mapping apparatus for analyzing a two-dimensional element distribution of a sample while scanning a sample stage, which includes an X-ray tube for irradiating the sample with an X-ray, an X-ray detector that detects a fluorescent X-ray generated from the sample, a pulse processor that discriminates X-ray energy and its intensity based on an output of the X-ray detector, a computer that processes a signal from the pulse processor, image pickup means for taking an optically observed image corresponding to a position where the X-ray intensity is obtained, a stage controller for driving the X-ray sample stage, and an image processing apparatus that displays an X-ray intensity distribution in a two-dimensional manner (for example, see Japanese Patent Application Laid-open Nos. Hei 04-175647, Hei 11-264805, and 2009-300232).
In addition, there is disclosed an X-ray mapping apparatus including a sensor for determining presence or absence of the sample at a measurement position in the above-mentioned structure of the apparatus (see Japanese Patent Application Laid-open No. Hei 11-264805).
X-ray mapping analysis is used for detecting a harmful substance contained in a composite electronic component, but it takes a remarkably long measurement time for analysis in a wide range. In Japanese Patent Application Laid-open No. Hei 11-264805, the presence or absence of the sample at the measurement position is detected so that the measurement time can be shortened. However, in analysis of a substrate on which many electronic components are mounted, there is a case where it cannot be determined whether or not the measurement is necessary based on only the presence or absence of the sample. For instance, there are problems that the measurement is performed even if there is a component for which the measurement is not needed on the substrate, and that the measurement cannot be performed because a region where a low profile component exists is erroneously determined to be a region without a sample. Therefore, sufficient reduction of the measurement time cannot be achieved.